P0744
Torque Converter Clutch Circuit IntermittentP0744 is a generic OBD-II powertrain diagnostic trouble code: Torque Converter Clutch Circuit Intermittent. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P0744 means
P0744 is stored when the TCM detects an intermittent malfunction in the torque converter clutch (TCC) circuit — the solenoid or its wiring is momentarily losing control or dropping out during operation rather than failing continuously. The TCC solenoid locks the torque converter's pump and turbine together at cruise speeds to eliminate slippage and improve fuel efficiency. When the circuit intermittently opens, the TCM cannot maintain commanded lockup state, and the clutch engages or releases unpredictably.
P0744 should be distinguished from P0741 (TCC stuck off — clutch never locks) and P0742 (TCC stuck on — clutch will not release). P0744 is specifically the intermittent variant: the system works correctly some of the time but loses control momentarily, which typically points to a wiring, connector, or solenoid coil integrity issue rather than a fully failed mechanical component.
When the TCC engages and disengages erratically the driver experiences a shudder or lurch at highway cruise, fluctuating engine RPM, and reduced fuel economy. Because the torque converter absorbs heat during slippage events, repeated uncontrolled engagement cycles can raise transmission fluid temperature and accelerate wear on the converter friction material.
Common causes
Most-frequently reported root causes when P0744 is logged.
-
1
Corroded, loose, or intermittently open connector pins in the TCC solenoid circuit.
-
2
Chafed or cracked wiring in the TCC solenoid harness causing intermittent open-circuit events.
-
3
Worn TCC solenoid coil with degraded insulation that breaks down under heat or vibration.
-
4
Contaminated transmission fluid fouling the solenoid orifice and causing inconsistent hydraulic response.
-
5
Low transmission fluid level reducing hydraulic pressure to the TCC apply circuit.
-
6
Debris or varnish buildup in the TCC valve body circuit causing intermittent mechanical sticking.
-
7
Faulty or intermittently malfunctioning TCM driver circuit losing the ability to control solenoid current.
Symptoms drivers notice
How to diagnose P0744
A typical diagnostic flow when this code is present.
-
1
Read all DTCs and freeze-frame data; note vehicle speed and engine load at time of fault to understand when lockup was commanded.
-
2
Inspect TCC solenoid wiring and connector for corrosion, bent pins, and chafed insulation; wiggle the harness with live solenoid command data streaming.
-
3
Check transmission fluid level and condition; contaminated or low fluid should be corrected before further electrical testing.
-
4
Measure TCC solenoid resistance and compare to manufacturer specification; an erratic or out-of-range reading indicates a failing coil.
-
5
Use a scan tool to command TCC lockup on and off while monitoring actual solenoid current to confirm the TCM driver circuit is functioning.
-
6
If solenoid and wiring pass, inspect the TCC apply circuit in the valve body for contamination or worn spool bores.
-
7
Replace the TCC solenoid if coil resistance tests borderline; confirm repair by road-testing at conditions that previously triggered the fault.
Related powertrain codes
- P0700 — Transmission Control System Malfunction
- P0701 — Transmission Control System Range/Performance
- P0702 — Transmission Control System Electrical
- P0703 — Torque Converter/Brake Switch B Circuit Malfunction
- P0704 — Clutch Switch Input Circuit Malfunction
- P0705 — Transmission Range Sensor A Circuit malfunction (PRNDL Input)
Frequently asked questions
What is the difference between P0744, P0741, and P0742?
P0741 means the TCC is stuck off and never achieves lockup. P0742 means the TCC is stuck on and will not release, which can cause stalling. P0744 is the intermittent variant — the clutch works but loses control momentarily, pointing to a wiring or solenoid coil integrity issue rather than a fully failed mechanical state.
Can I drive with P0744 active?
Short-term driving is generally possible, but repeated uncontrolled TCC engagement cycles generate excess heat in the torque converter and fluid. Fuel economy will suffer and, if left unrepaired, the friction material in the converter can wear prematurely.
Is the torque converter itself likely to need replacement for P0744?
Not necessarily. P0744 is primarily an electrical/circuit intermittent fault, so the solenoid and wiring should be thoroughly diagnosed before condemning the converter. However, if the friction material inside the converter has degraded from repeated uncontrolled slipping, replacement may be required alongside the solenoid repair.
Will changing the transmission fluid fix P0744?
A fluid service can resolve P0744 if contaminated fluid was fouling the solenoid orifice or causing valve body sticking. It is a sensible first step and low risk. However, if the root cause is a failing solenoid coil or wiring fault, a fluid change alone will not provide a lasting fix.
Disabling P0744 in software
RaceTune can permanently disable P0744 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
Got P0744 in your scan?
Upload your ECU file — we'll identify the exact software version and confirm whether a disable is available for your car.
Upload your file